etherfandomcom-20200213-history
Phonebot developer's reference/Script language
Operators and literals Strings: "Delimited by double quotes." Numbers (integers and floating-point): 0 1 2 3.14 9.9999 Boolean: true false Variables and basic types Variables are created the first time they are referenced. The first reference must be a write action as opposed to a read action. The first two lines are valid and the third is not: temp1 = "New variable." control1.text = temp1 control1.text = temp2 /* invalid: temp2 was never initialized */ Variables are dynamically typed and so can hold a value for any intrinsic data type. All below are valid: temp1 = "New variable." temp1 = 12 / 4 temp1 = 12.0 / 5.0 /* temp1 = 2.4 */ temp1 = "Result is: " & (12 / 4) /* temp1 = "Result is: 3" */ temp1 = (12 / 4) + "9" /* temp1 = 12 */ temp1 = false temp1 = (12 / 4) 3 /* temp1 = true */ The intrinsic data types are: Complex types Variables can be coerced into different types. This means that a variable must be told it's a specific type in order to use the type's properties and methods. The second and third lines below show the variable temp1 being coerced into a database type: temp1 = application1.get_database("contacts") db_size = temp1:database.size new_record = temp1:database.add_record() The coercible types are: Use uncoerced variables to access the intrinsic value of the variable. A variable must be coerced to a type in order to use the type's properties and methods. temp1 = "A string value." temp2 = temp1 /* copy the intrinsic value, temp2 = "A string value." */ temp2 = temp1:string.size /* coerce to access the string size, temp2 = 15 */ Scope Variables are defined within a specific scope. A variable's scope determines where it can be accessed. By default, variables are in local scope and can only be accessed from the event where they are defined. Variables in module and application scope can be used to pass data between scripts. For example, a button's OnClick event could set the value of a module variable, and a different button's OnClick event could read that value to perform a calculation. Similarly, a module could store the value of an edit control within an application variable, and a different module could read that value to display in a label. The following script illustrates the syntax for the three scope levels: temp1 = "local scope" edit1.text = temp1 module1.temp1 = "module scope" edit1.text = module1.temp1 application1.temp1 = "application scope" edit1.text = application1.temp1 temp1 can be referenced only within the current script. module1.temp1 can be referenced within any script within the module and will retain the last value set. application1.temp1 can be referenced within any script within the application and will retain the last value set. Visual and container types Visual and container objects are anything that the user interacts with. Visual types include items such as buttons and edit controls; container types consist of modules and applications. Visual types are also called controls. :Note: In computer science, type, class, and object all have specific definitions. Here, they will be used in the following more general sense: :*''Type'' - A distinct data item with specific characteristics. Integers, strings, databases, and edit boxes are all types. Some types may share characteristics: both edit boxes and labels can display text. Others have unique characteristics: integers can be added together but databases cannot. :*''Object'' - An object is an instance of a type. A specific integer object may equal 5 and because it is an integer type, it can be added to another integer. A specific label object may have its text property set to Hello, world!. In addition to properties and methods, visual and container types have events. Events can contain script to be executed when something happens to the object. Visual types have OnClick. Container types have OnOpen, OnClose, and OnService. Within an event, the object whose event is being fired can be referred to by its name or with the special keyword this. this enables you to copy the same code to different objects' events and have it perform the same. /* in button1.on_click, updates button1 */ this.text = "clicked!" /* in button2.on_click, updates button2 */ this.text = "clicked!" Control structures Assignments copy one value to a variable or object property. The right-hand side of assignments can use variables, object properties, literals, or complex expressions. temp1 = temp2 /* assumes temp2 was defined elsewhere */ temp1 = application1.name temp1 = 5 temp1 = (12 / 4) * temp2 Methods take zero or more arguments and request an object to perform an action. A method may return a value or object as a result. application1.open_module("module1") db = application1.get_database("contacts") /* store the database into a variable */ db_size = db:database.size /* coerce db into a database object and store the size */ Conditionals test one or more expressions and process a block of script based on the first test that returned true. if (temp1 < 0) msg = "Negative number" elseif (temp1 0) msg = "Zero" elseif (temp1 < 10) msg = "Positive number, less than 10" else msg = "Positive number, 10 or greater" end Loops process a block of script zero or more times based on the value of a counter. msg = "List of numbers zero through nine: " for (index = 0; index < 10; index = index + 1) msg = msg & " " & index end Category:Phonebot